Phonophobia and brainstem excitability in migraine.

Phonophobia in migraineurs may be due to lower hearing threshold (HT) and higher brainstem neuronal excitability. We report the correlation of phonophobia in migraineurs with HT, brain stem auditory evoked potential (BAEP) findings, and auditory triggers. Sixty-one migraineurs and 101 controls were included for HT, of whom 59 migraineurs and 31 controls had BAEP studies. Clinical details, migraine triggers, and headache frequency were noted. Hearing threshold was measured, and amplitudes of waves I to V of BAEP studies were measured. Migraineurs had lower HT compared with controls (41.61 ± 5.25 versus 45.39 ± 6.26 dB; p < 0.001) especially in chronic migraine (40.24 ± 4.81; p < 0.001). Hearing threshold correlated with headache frequency (p < 0.05) and auditory, visual, and tactile (p < 0.05) triggers. Hearing threshold was lower during headache (p < 0.001). Wave II, III, and IV amplitudes of BAEP were higher in migraineurs than the controls. Wave II (p < 0.05) and III (p < 0.05) amplitudes correlated with HT. Migraineurs have lower HT, especially in those having chronic migraine, ictal HT recording, and multiple sensory triggers. Higher amplitudes of BAEP waves in migraineurs and their relationship with the frequency of headache and HT suggest the sensitization of brainstem auditory neurons.